1. Technical Field
The present invention relates to an image pickup device and a projector.
2. Related Art
A projector known in the art modulates light emitted from a light source according to image information, and projects the modulated light with magnification onto a projection surface such as a screen. Recently, such a technology has been proposed which overlaps figures, characters or the like on an image projected from the projector for display (for example, see JP-A-2011-2650).
A projector disclosed in JP-A-2011-2650 includes an image pickup device, and constitutes a display system functioning as an interactive white board system when used in combination with a pointing device capable of emitting infrared light from its tip, and a PC (personal computer) functioning both as an image output device and an image analyzer. The image pickup device has a camera disposed inside an opening formed in an outside casing of the image pickup device, which opening is closed by a cover capable of transmitting infrared light. The camera of the image pickup device detects infrared light emitted from the pointing device when the pointing device is operated on a projection surface. Based on the detection of the infrared light, the projector overlaps figures or the like corresponding to the track of the movement of the pointing device on the original image, and projects the resultant image.
Though not explained in detail in JP-A-2011-2650, it is assumed that the cover of the projector through which infrared light is transmitted is made of material capable of cutting wavelengths of lights such as visible light other than infrared light so as to prevent the camera from receiving light other than the infrared light emitted from the pointing device and recognising the received light as the infrared light.
According to the projector disclosed in JP-A-2011-2650, the infrared light emitted from the pointing device can be detected by the camera and overlapped on the original image for projection of an overlapping image, in this case, however, an image corresponding to visible light other than the infrared light is difficult to be captured by the camera. Thus, according to the projector disclosed in JP-A-2011-2650, an image projected on the projection surface is difficult to be captured by the camera, wherefore the original image is difficult to be processed by using the image projected on the projection surface. For example, when control patterns associated with calibration of the position of the pointing device on the projection surface, and distortion of the projected image are not allowed to be obtained by the camera, calibration and image distortion correction are difficult to be automatically performed. In this case, manipulation of the projector becomes complicated.